Blowpipe



C. LAING.

BLOWPIPE.

APPLICATION FILED MAY 24, 19m.

Patented May 31, 1921i.

UTTTTT sT-Tas TTenT @Tence CLAYTON LAING, 0F CHICAGO, ILLINOIS.

BLOWIPIPE.

Lerares,

Application iled May 24.,

State of Illinois, have invented certain new` and useful mprovements in Blowpipes, of which the following is a specification.

My invention relatesto a blow pipe or torch, and more particularly to a device of this sort for use by dentists, jewelers or other metal workers for soldering, welding and other like operations.

A blow pipe of the type which my invention seeks more. particularly to improve upon, employs gas as a fuel and is used in connection with a supply of compressed air delivered to the point of combustion of the gas. lt has been proposed to provide a blow pipe of this sort with separate control valves for the gas and air conduits by means of which the volume of flame and also its character may be varied by increasing or decreasing the amounts of gas and air delivered to the combustion point, changing when necessary the ratio of air to gas. But .the inconvenience of having two valves to c ontrol, especially the loss of timein making adjustments necessary to obtain the proper quantities of the uids at the right proportions for the particular operation and the liability of having the flame blown out by excess, of air make this arrangement quite impractical for some kinds ,of work. Blow pipes have also been used having gas and air valves geared or otherwise connected t0-v gether for operation in synchronism, that is to say, for. the purpose of increasing and decreasing .the air proportioned with the increase and decrease of the gas flow. But this arrangement gives no opportunity for changing at will the ratio between air and gas to vary the character ofthe llame; and this is very desirable, and, in fact, necessary, for certain operations. For this and other reasons manually governed blow pipes utilizing compressed air have not come into very general use. Jewelers, for example, still employ, ordinarily, the mouth blow pipe which, although its use involves many inconveniences, is capable of a delicacy of control possessed, So far as Iam aware, by no blow pipe having manual control wh1ch has been produced prior to .my 1nvent1on.

One of the objects of my inventlon is to provide controlling means for a blow p1pe, torch or other like instrument, whereby,

Specification of Letters `Patent.

Patented May 311, 11921. 1918. Serial No. 236,390.

through the movements of a single controlling element adapted to be moved by the thumb of the operator, for example, the increase or diminution of gas supplied to the polnt of combustion will be accompanied by an lncrea'se or dimunition of the air, but at a ratlo, as betwen air and gas, which may be varied at the will of the operator, so that the singlercontrolling element governs both vthe volume of the flame and also its character which is dependent on the proportion maintained between the fluids.

A 'further object of the invention is to provide an arrangement whereby the shutoH'or diminution of the iow of air through the instrument does not involve any excessive pressure back of the point where the shut off takes place; this result being accomplished by providing an exhaust port controlled in synchronism with the air port or 4ports to which the air passes to the combustion point, so that said exhaust port is opened when said air port or ports are closed and closed when the same are opened. In a blow pipe the gas receiving pipe and the air receiving pipe are connected by iexible tub-ing with their respective supply lines. In operation the valve at the gas supply line is opened and, with both air and gas valves in the blow pipe opened, enough air is turned o-n. from the valves inthe air supply line to produce the maximum blast flame. In the ordinary blow pipe, as soon as the flow of air is substantially diminished or cut oli', the airl pressure back of the valve in the blow pipe approximates o-r equals that within the supply llne or tank. This equalization of pressure under these circumstances may involve the blowing o' of the connecting tube ifthe supply pressure is high and, in any event, under such pressure it is difficult to controlv the air for the finer and more ydelicate llames. Again, if it were possible to so construct a blow pipe and connecting tube to withstand this pressure, if the gas and air valves were operable in synchronism and proportioned to operate from an air supp-ly of one pressure they would not do so when attached to a supply of a different pressure.

It will be apparent that the two improvements outlined above, which constitutethe,

primary objects of my invention, are susceptible of use singly as well as conjointly; although to get the best results both expedients must be employed. When both are Sii used, in' the manner to be hereinafter described, a `blow pipe is provided having a manual air control which is delicate and accurate enough so that the instrument may be used on operations that ordinarily have necessitated the use of the mouth blow pipe. In soldering. and welding loperations involving small pieces of metal which have to be accurately placed the operator has one'hand engaged holding soldering pliers or the like and ordinarily the melting operations must be performed with rapidity. Where such operations lnecessitate changes in the character of the ame such changes must be brought about very expeditiously and by movements which can be executed more or less automatically or subconsciously. The device of my invention meets these requirements fully.

The invention is illustrated, in a preferred embodiment,'in the accompanying drawing wherein- Figure 1V is a longitudinal sectional view of a blow pipe constructed in accordance with `the invention.

Fig. 2 is a plan view of the same.

Fig. 3 is a vertical sectional view on line 3--3 of Fig. 1. y

Fig. 4 is a sectional plan on line 4-4 of Fig. 3.

Fig. 5- is a diagrammatic view showing the relation of the several coperating ducts and ports in the control valve and valve casing, the rectangular figure representing a development of the valve ynasing as the casing would appear if it were severed on a longitudinal linev at the bottom of the casing and iattened out, and

Fig. 6 is a view, in perspective, of the controlling valve.

Like characters of reference designate like parts in the several figures of the drawing.`

Referring to the drawing, A is a gas receiving pipe adapted to be connected, for example, by a rubber hose A with a supply of gas, B an air receiving pipe similarly connected by hose B with a supply of com- -pressed air. C is a gas delivery pipe, D the air delivery pipe located within pipe C, E a tubular member forming a casing for the cylindrical control valve F, and G an exhaust pipe which is arranged between pipes .A and B; pipes A, B and G being preferably bent'to form a handle for the instrument.

Pipe Ak is divided 4) to provide what might be termed an inlet chamber designated 11, andan outletv 1chamber designated 12, the pipe and valve-'casing E being provi-ded with inlet and outlet ports 13 and 14 on, opposite sides of partition 10, and pipes A and C with a port 15'. y

A partition 16 divides air pipe B into the inlet chamber 17 and outlet chamber 18. A port 19 leads from chamber 17 to the valve `livery pipe D.

by a partition 10 (Fig.-

chamber E and a port 20 from the valve chamber to chamber 18. Arranged within the inner portion of gas pipe C against the end of air pipe D is a partition 21, this partition being formed with a port 22 and a port 23 being provided between the air outlet chamber 18 and the space 24 at the inner en-d of pipe C whereby air .from pipe B after passing the valve F, as will be hereinafter described, will enter the air de- The valve F is preferably a solid cylindrical member arranged in the valve casing E so that it may be moved longitudinally thereof and also rotated therein to the extent permitted by the slot 25 formed in the top of the valve casing through which projects a stud 26 provided with a button or knob 27 for the thumb of the operator. The valve is formed with a longitudinal groove 28 preferably of the same width and depth for the major part of its length but tapered at one extremity as indicated at 29 (see the valve, the position shown in the drawings, the tapered end29 of duct 28 overlaps slightly the gas outlet port 14. In all positions of the'valve duct 28 is in communication with the gasinlet port 13. In the position of the valve shown enough gas will be delivered to the combustion point of the blow pipe, that is, to the opening 30 in the en-d of pipe C to maintain a pilot flame. As the valve is moved forward the effective opening'between the gas duct and the gas lIn other words, the air is shutoff in this position of the valve. As the valve is moved forward, that is to say, longitudinally in the casing E, the pointed end 32 of the duct 31 intersects the air outlet port 20 providing anorifice for the outflow of the air which increases with the forward movement of the valve. Considering only the longitudinal movement of the vvalve', that is, assuming that when it is moved forward it is not rotated, the amount of air delivered to the combustion point has a fixed relation to the amount of gas for any position of the valve. Preferably the ducts are so designed as to make this relationship a constant ratio. To vary this ratio, that is, to increase or decrease the proportion of air to gas, the but! Figs. 4 and 5). In the retracted position of Lerares tice the valve may, of course, be rotated and moved longitudinally at the same time. The

rotation of the valve, as has been stated,

does not, in the preferred arrangement of the ports shown, affect the flow of gas; but so far as the air is concerned, it brings about a diminution or increase of the effective size of the controlled air orifice due to the fact that the edge 33 of the air duct 20 which is intersected by the tapered end 32 of duct 31 is oblique to the axis of the duct instead of being at right angles thereto asin the case of the gas outlet 14. By these arrangements the flow of air through the instrument is synchronized with the flow of gas, the increase of flow of gas involving an increased flow of air, and vice versa, but the ratio between gas and air may be varied at the will of the operator. While it is desirable to have the gas vary only With the longitudinal movement of the valve and the air vary both with longitudinal movement and the rotation of the valve, as shown, this is not the only arrangement possible. The gas might be cut off on rotation of the valve while the air How remained constant, or both air and gas might be varied at both movements of the valve.

The other feature of my invention, the arrangements whereby undue air pressure in the instrument is prevented when the iow of air therethrough is diminished, will next be described. The desired result is accomplished by providing a controllable air exhaust port, the controlof which is synchronized with the control of the air passing to the combustion point so that when the iiow of air through the air delivery pipe is out off or diminished the exhaust orifice is opened to the extent required to prevent accumulation of pressure; With this object in view the air duct 31 is formed with a branch 34 leading to a tapered duct 35 which intersects an air exhaust port 36 that is conformable to the controlled air port 20 but oppositely disposed with respect thereto.

The port 36 is arranged in the bottom of thev valve chamber (Fig. 1) and communicates with an opening in the exhaust pipe Gr. 'Ihe exhaust pipe might be dispensed with. Its purpose is simply to carry the exhaust to a convenient point away from the work. rIhe exhaust pipe is formed at its lower extremity with a perforation 37. It will be understood that the dimensions of the several ports of the air system are calculated,

with respect to the resistance to the air flow presented by the conduits or series of passageways and orlices through which the air mustpass tothe point of. combustion and to the exhaust opening so that the movement` of the valve F, either forwardly, backwardly or rotationally, will not involve any accumulation of pressure in any part of the air system. When the valve is moved forwardly the e'ective size of the orifice provided by the outlet port 20 and the tapered end 32 of the air duct is increased. At the same time the eective size of the corresponding orifice provided by the tapered end 35 of the duct and the air exhaust opening 36 is proportionately decreased. Corresponding proportional increase and decrease in the sizes of these openings is brought about by the rotation of the valve. The drawing, it will be understood, illustrates only approximately the proper dimensions of the several air ports and passageways, this matter being one of suitable mechanical design.

While I have described my invention in a preferred embodiment, it will be' understood thatthere may be considerable modification in the mechanical structure disclosed without departure from the principles of the invention. vTherefore I do not wish to be understood as limiting the invention to the arrangements, constructions and devices shown and described except-so far as the claims hereto appended may be specifically so limited.

I claim:

1. Ina blow pipe, governing means for the gas and air comprising a single controlling element by the movements of which the iiow of gas and air may be increased or decreased synchronously in proportions variable at will.

V2. In a blow pipe, governing means for the air and gas comprising a single controlling element having two ranges of movement, one effecting the increase and decrease of gas flow to the combustion point and, synchronously therewith, the increase and decrease of air thereto, the other bringing about a variation in the proportions of air and gas.

3. In a blow pipe, governing means for the gas and air comprising a single controlling element longitudinaly movable to vary the flow of gas to the combustion point and, synchronously therewith, the flow of air thereto, and rotatable to vary the proportions of air and' gas.

d. The combination with a blow .pipe having a nozzle, of means for supplying air and gas thereto, and controlling means comprisinga single controlling element for increasing and decreasing-the flow of airand gases through said nozzle synchronously and in proportions variable at will.

5. In a blow pipe, the combination of gas and air receivingand delivery pipes, a valve casing and a valve movable longitudinally androtatably in said casing, said pipes, A"casing and valve being provided with gas and air ports arranged so that the longitudinal movement of the valve increases or decreases, according to the direction of said movement, the iow of gas and air to said delivery pipes, respectively, While the' rotation of the valve increases or decreases, according to the direction thereof, the How of .air without affecting the flow of gas.

increases or decreases, according to the di` rection of said movement, the fiow of gas vand air to said delivery pipes, respectively, while the rotation of the valve increases or decreases, according to the direction thereof, the flow of air without aecting the flow of gas.

7'. The combination with a blow pipe, of gas receiving and delivery pipes having gas inlet and outlet ports, respectively, associated ,therewith, air-receiving and delivery pipes having air inlet and outlet ports, respectively, associated therewith, and controlling means comprising a single controlling element for said gas and air ports for increasing or decreasing the flow of air and gas synchronously and in proportions variable at will. 8. In a blow pipe, the combination of gas receiving and delivery pipes, air receiving and delivery pipes, a valve casing having gas inlet and outlet ports communicating with said gas receiving and delivery pipes, respectively, and air inlet and outlet ports communicating with said air receiving and delivery pipes, respectively, and a valveslidable in said casing and capable of being held in any desired position by friction formed with a duct toput said gas inlet andoutlet ports in communication with each other and with a duct to put said air inlet and Youtlet ports in communication with each other; the extremities of the ducts which coperate with said outlet ports, respectively, being tapered, for the lurpose described.

9. In a blow pipe, the combination of gas receiving and delivery pipes, air receiving and delivery pipes, a valve casing having gas inlet and outlet ports communicating with said gas receiving and delivery pipes, respectively, andair inlet and outlet ports communicating with said air-delivery pipes respectively, and a valve slidable and rotatable in said casing formed with a duct to lput said gas inlet and outlet ports into coinmunication with each other and with a ductv to put said' air inlet and outlet ports into communication with 'each other; said ports and ducts being conformed so that the longitudinal movement of the valve in opposite directions increases and decreases the fiow of gas and therewith the flow of air to the respective delivery pipes, while the rotation ganaron of the valve operates to vary the proportion of air and gas.

10. In a blow pipe, the combination of gas receiving and delivery pipes, air receivlng and delivery pipes, a valve casing having gas inlet and outlet ports communicating with said gas receiving and delivery pipes, respectively, and air inlet and outlet ports communicating with said airl delivery pipes, respectively, and a valve slidable and rotatable inl said casing formed with a duct to putsaid gas inlet and outlet ports into communication with each other and with a duct to put said air inlet and outlet ports into communication with each other; the extremities of said ducts coperating with said outlet ports, respectively, being tapered for the purpose described, and the edge of the gas outlet port intersected by the gas duct being at right angles to the axis of said duct while the edge of the. air outlet port intersected by the air duct is oblique to the axis i of said duct. 11. A blow pipe having an orifice through which air passes to the combustion .point and an exhaust orice, in combinationwith means for simultaneously controlling said orices to maintain substantially uniform air pressure in the instrument,

.12. A blow pipe having an orifice throaigh which air passes to the combustion point and an exhaust orifice, in combination with means for simultaneously controlling said orifices comprising a single controllable element, the movement of which opens the exhaust orifice to the extent that the other orifice is closed, |and vice versa, whereby substantially the same pressure is maintained in the instrument.

13. A 'blow pipe having an orifice through which air passes to the combustion point and an exhaust orifice, in combination .with means for simultaneously controlling said orices comprising ,a' single valve which' opens the exhaust orifice to the extent that the other orifice is closed, and vice versa.

14. A blow p-ipevhaving orifices through lwhich gas and air pass to the combustion point, and an exhaust orifice, inl combination with means for simultaneously controlling said orifices to increase or decrease gas and air flow in synchronism and to maintain substantially uniform'air pressure in the inisa raras/oe point and an exhaust orifice, in combination with means comprising a single valve for simultaneously controlling said milices to increase or decrease gas and air flow in synchronism and to maintain substantially uniform air pressurein the instrument.

17. A blow pipe having orifices through which gas and air pass to the combustion point, and an exhaust orifice, in-combination with means for simultaneously controlling said orifices to increase or decrease gas and air iow in synchronism and to maintain substantially uniform air pressure in the instrument in proportions variable at will.

18. A blorw pipe having orifices through whichl gas and air pass to the combustion point, and an exhaust orifice, in combination with means comprising a single controllable element for simultaneously controlling said orifices to increaseor decrease gas and air flow in synchronism, and to maintain substantially 'uniform air pressure in the instrument in proportions variable at will.-

19. A'blow pipe com rising, in combination, air receiving lan delivery pipes, a valve chamber having inlet, outlet and exhaust ports, yand a valve in said chamber having a duct to connect said ports; said ports land duct being formed so that the movement oaf the valve in one direction increases the How of air to the delivery pipe and proportionately diminishes How though the exhaust port, and vice versa.

20. A blow pipe comprising, in combination, Iair receiving and delivery pipes, a valve chamber having inlet, outlet and exhaust ports, and a valve slidably arranged in said chamber having a duct which extends across said inlet pofrt and has tapered extremities adapted to intersect said outlet and exhaust ports, respectively.

21. lln a blow pipe, the combination of gas and air receiving and delivery pipes, a valve chamber and a valve movable longitudinally and rotatable in said chamber; said chamber and pipes being formed with gas inlet and' outlet ports and air inlet and outlet ports and the chamber with an exhaust port, and said valve with gas and air ducts rarranged so that the movements of the Valve longitudinally and rotationally control the ofw of gas and air to the combustion point in variable proportions and synchronously therewith control the outflow of air through the exhaust port so as to maintain substantially uniform pressure' in the instrument.

22. In a'blow pipe, the combination of gas and air receiving and delivery pipes, a valve chamber having gas inlet and outlet ports communicating with said gas receiving and Idelivery pipes, respectively, air inlet and outlet pofrts communicating with said air receiving `and delivery pipe, respectively, and an exhaust port on the opposite side of the air inlet port from the air outlet port, and a valve slidably and rotaltably arranged in said chamber formed with a gas duct crossing the gas inlet portewhich has a tapered extremity adapted to intersect the gas outlet port and formed with an air duct extending across said air inlet port having tapered extremities, one of which is adapted to intersect the air outlet port, the other the exhaust port; the gas outlet port being conformed so that the rotation of the valve does not change the effective size of the orice between the gas duct and said port, while (said air outlet and exhaust ports are conformed so that the rotation of the valve in one direction diminishes the eective size of the orifice between the air duct and the air outlet proportionately increasing the eective size of the orifice between said air duct and the exhaust ports, and vice versa.

- 23. A blow pipe having a line for supplying air -under pressure thereto, means for varying the supply of air to the combustion point and means for preventing the accumulation of back pressure in the air lsupply line when the supply of air to -the combustion point is decreased.

CLAYTON LMNG., 

